The Argentina forward blasted home from 25 yards after just six minutes of the game at the Allianz Stadium, before Leonardo Bonucci and Cristiano Ronaldo rounded off a routine win.
It was Dybala's first league goal since the 3-1 defeat of Cagliari on November 3 and just his eighth in 29 appearances in all competitions.
Allegri, though, says the 25-year-old's all-round performances have been hugely important to Juve, even if his goalscoring has been limited by playing behind Ronaldo and Mario Mandzukic.
"I'm happy for Paulo. He scored a good goal and forwards live for that," Allegri told Sky Sport Italia .
"We need a player who works between the lines, even more so this year as we play with two strikers as well as him.
"This has maybe limited him a little in terms of finishing, but not in terms of the matches and his performances."
Juve's win stretched their lead at the top of the table to 14 points, having played a game more than Napoli, and ensured they head to Spain for Tuesday's Champions League last-16 first leg with Atletico Madrid in positive spirits.
Allegri is eager for them to get at least an away goal at the Wanda Metropolitano if they are to have hope of reaching the quarter-finals.
"The team is growing physically. We struggled a bit after the break but we're now ready to face this important moment of the season, both in the league and the Champions League," he said.
"It'll be a different game in Madrid. We will have to pay great attention and go there with the aim of scoring, otherwise going through will be tough."
The Italian boss also expected to see "an open match" in Madrid, believing that Diego Simeone's club will try to play on the front foot on their home turf.
"Atletico plays very aggressive football when playing at home. It is a team that has had great results in previous years in Europe.
"It is an open match, we have as much chance to go through as they do.
"The first thing we must do is score a goal in Madrid. Scoring in Madrid will be decisive for our qualification."